Self-retaining cartridge



Aug, 23, 1932. F. H. ARMSTRONG sELF RETAINING CARTRIDGE Fi1ed,A'pri1 24, 1929 l NN Q `langsam! Aug. "23, 1932 FRANK H. ARMSTRONG, OF CHICAGO, ILLINOIS, ASSIGNOR TO SAFETY MINING- COM- PANY, F CHICAGO, ILLINOIS, A. CORPORATION snm-anmmue CARTRIDGE 'a application :ned april 24, 192e. serial no. 357,653.

The present invention relates to blasting cartridges of that type which usually comj prise a rigid metallic container' having a discharge opening normally obstructed by a f venting means in the form of a valve, rupturable disc, or the like. This type of cartrid e is preferably, although not necessarily, use in connection with blasting charges of a liquefied gas such, for example, as carbon a: dioxide. A suitable cap is provided for securing the venting device or rupturable disc against the discharge end of the cartridge Aand such cap usually comprises a chamber for receiving the released charge and a plurality of ports for directing the charge outwardly of the cartridge. In cartridges using a liqueied gas as the blasting medium, a suitable heating means is provided for reconverting the charge to the gaseous state after the cartridge has been placed in the position in which it is to be discharged, thus greatly increasing the internal pressure of the cartridge and causing the venting means to operate and release the charge into the u material to be blasted. A cartridge of this general type is shown in the patent to Dent Ferrell and Arthur W. Helmholtz, issued May 19, 1931, as Patent No. 1,805,541, entitled Blasting cartridges. For a more de- 50 tailed explanation of the structure and use of this type 'of cartridge, reference may be had to this application. v

In blasting with cartridges of this type, it is customary to drill a hole, commonly known as a shot hole or drill hole, in the material which is to be blasted, such hole being of suitable diameter to receive the blasting cartridge. The cartridge after being charged, is adapted to be inserted in the drill hole, pushed back to the remote end thereof and the hole is thereafter filled and tainped to firmly confine the cartridge andthe charge' liberated thereby to the remote end of the drill hole.' However, it has been found' in practice that the filling and tamping of the drill hole as ordinarily practiced` is not a. dependable means for retaining the cartridge in the desired position at the remote end of the hole.

For some reason, it seems that the tamping 1s in some instances incapable of holding the cartridge in place, and when such an instance arises, the cartridge, together with .the tamping material is blown entirely out of the drill hole, thus giving rise to the possibility of injury to either life or property7 and greatly diminishing the eiect of the discharge upon the material to be blasted. The logical explanation for this action seems to be that the released gases find their Way between the end of the cartridge and the remote end of the drill hole and thus react upon the cartridge in a manner to force the same in an axial direction through the hole. This action is probably similar to that of a compressed gas introduced between the end of a piston and the head of a cylinder.

In view of these practical difficulties, it is apparent that some means for positively holding the cartridge in position within the drill hole is to be desired. Accordingly it is an object of my invention to provide such a means.

More particularly, it is an object of my invention to provide a holding means which is directly associated with and carried by the cartridge.

Another object of my invention is to provide a cartridge containing means capable of acting with a force substantially commensurate with the force of discharge of the cartridge.

A further object of my invention is to provide a discharge cap having mechanical means therein which are rendered operative by the discharge of the cartridge fori. retaining the same in thedrill hole.

Specifically, it is an object of the invention to provide a plurality of gripping dogs' or anchors which are capable of being projected outwardly into engagement with the wall of the drill hole by and in proportion to the force of the discharge.

Other objects and advantages of the present invention will appear in connection with the description of the drawing, wherein,

Fig. 1 is a view'in side elevation and partly in section of a blasting cartridge embodying my invention,

Fig. 2 is a top plan view of a portion of the discharge cap shown in Figure 1,

Fig. 3 is a transverse section taken on line 3-3 of Figure l,

Fig.l 4 is a transverse section taken on line 4--4 of Figure 1.

The cartridge *retaining means of the present invention is in the nature of an improvement upon the invention of David Hodge shown in pending application, Serial No. 355,279, filed April 15, 1929 and entitled Self retaining cartridge. l

Referring to Figure 1 it will be noted that the cartridge comprises a casing or container 1, havin g an internal charge receiving chamber 2 and a reduced neck portion 3 surrounding the discharge opening 4. A cap 5 is adapted to be fitted over the 4reduced portion 3 of 'the container and this cap is provided with an annular recess 6 wherein is located a hardened steel ring 8. The cap is provided with an inwardly extending radial shoulder 7 for axially confining the ring 8. Interposed betweenthis ring and the adjacent end p of the reduced portion 3 of the container 1s a disc 9 of relatively mild steel which is adapted to give way or be ruptured when a predetermined pressure is reached within the container. 1n this connection, it is noted that the hardened steel ring 8 serves as a shear ring for the disc 9 to determine the line of 'breakage thereof. For the purpose of providing an effective seal between the rupturable disc and the end of the container, the latter is provided with a knife edge sealing ring 10, which is preferably of relatively hard material .so that it may be impressed into the disc 9. This sealing ring is preferably formed eccentrically with respect to the axis of the container so that relative rotation of the disc 9 and the container will be effectively prevented.

The discharge cap 5 is provided internally with a ch amber 11 which is adapted to receive the charge released from the container.. A pluralityT of discharge ports 12 and 14 radiate from the chamber 11 and serve to direct the liberated charge in a direction substantially transverse to the axis of the cartridge and of the drill hole. The cap is further provided with an axial opening 15 which is adapted to receive a suitable tool for the purpose of dislodging any obstruction which mlght occur in the chamber 11 of the cap.

The construction thus far described forms no part of the present invention except inso far as it cooperates with elements hereinafter described.

The end of cap 5 is provide parallel bores 16 as shown in and tted within each of the: of spaced bushings 17. Th adapted to have a tight t w tive bores and are preferably Each pair of bushings 17 is transverse pivot pin 18 and whereon the anchoring eleme These pivot pins are prefera the bores of the bushings so a fit therein.. Positioned on t and 19 and intermediate the of bushings 17 are the ancho and 21 respectively. These the form of dogs which hav ends adapted to engage the hole. The anchoring element erably have a loose fit about spindles in'order that any str be imposed upon these elem imparted to the pivot pins. elements are provided wi1 cylindrical hub portions, the s are adapted to have bearing e corresponding surfaces so fo charge cap in order that a anchor elements may be imp and sustained by the cap.

It will be observed by refe] that one pair of ports leadil tral chamber 11 in the cap are rectangular cross section. T discharge ports merge into the body of the discharge caj vided to accommodate move choring elements. Thus, it the anchoring elements are c ment from the full line positi ure 1 wherein they substanti discharge ports 14.- to the do( of Figure 1 wherein they ai wardly beyond the surface cap and into anchoring pos that the movement of the an may be definitely limited in that the movement of the cartridge toward the'expanded gas Vis liberatedV by the rupturthe remote end of the hole is such as to tend to retain the anchoring elements in restracted position. It will be understood, of course, that when the cartridge is discharged the tendency of the discharge is to force the cartridge in the opposite direction from-which it has been introduced. At the time of discharge ing vof the disc 9 into the chamber 11 of the discharge cap and with great force seek to escape through the four radial discharge ports therein. The ports 12 are-substantially unobstructed and a considerable portion of the liberated gas passes outwardly through these ports. However, the ports 14 are obstructed by means of the anchoring elements, but these are substantially instantaneously .moved outwardly by the force of the discharge, thus permitting the escape of the gases through all four of the discharge ports, while at the same time serving to move the anchoring elements into active position. Once these elements have been forced into the walls of the hole. The result is that the carthe cartridge in an axial direction serves to' further embed the anchoring elements in the walls of the hole. The result is that the cartridge is firmly anchored to the material to 'be blasted and that it remains in position With respect to the material so that the most effective results are produced. In practice, it has been found that a self anchoring cartridge of this type will usually be found with the material which has fallen as a result of the blast and in the immediate vicinity of that portion of the material to which it was anchored.

It should be understood that the specific disclosure herein made is for purposes of illustration only, and that the principles of my invention may be embodied in a variety of structural forms within the spirit and scope thereof, as defined in the appended claims.

Having described my invention, what I claim is:

l. A blasting cartridge having thereon a pivoted anchor which is engageable with the wall of a shot. hole to prevent flying of the ,cartridge when discharged, said anchor being positioned to be actuated by the gas dis-` charged from said cartridge.

2. A blasting cartridge adapted to be positioned within a shot hole and to be discharged therein, the discharge producing a force component tending to move said cartridge axially of the shot hole, anchoring means pivotally mounted on said cartridge and means for moving said anchoring means into engagement with the wall of the shot hole in response to the discharge of the cartridge. 3. A sitioned in a shot hole and to be discharged therein, a pivoted anchor carried by said cartridge and 'normally disposed wit-hin the confines thereof, said anchor being projected beyond the confines of said cartridge and into engagement with the wall of the shot hole in response to the discharge of the cartridge.

4. A blasting cartridge having a discharge cap with discharge apertures therein, in combination with meansdisposed in one of said apertures and movable in response to pressure therein to be projected beyond the confines of the cartridge to anchor the same.

5. A blasting cartridge having a discharge cap with discharge apertures therein, a plurality of anchor members pivotally mounted on said cap and having portions thereof overlying said apertures, whereby the force of discharge through said apertures moves said anchor members outwardly.

6. A blasting cartridge comprising a container filled with a blasting charge, a rupturable wall closing said container and a discharge cap having en agement with said container for holding said rupturable wall in place, said cap having a central chamber adapted to be placed in communication with the interior of said container by the rupturing of said wall and a plurality of discharge posts in said cap extending substantially radially outward from said chamber, and a plurality of anchoring dogs pivotally mounted on said cap and each having a portion overlying one of said ports, whereby the pressure of the discharge through said ports moves said dogs outwardly into anchoring position.

7. A blasting cartridge adapted to be p ositioned within a shot hole and to be d1scharged therein, in combination with an anchor member having a hub pivotally mounted on said cartridge and cooperating supporting and bearing surfaces formed on said container and the exterior of said hub.

8. A blasting cartridge adapted to be, positioned within a shot hole and to be discharged thcreln, sa1d cartridge having a slot formed therein, a pivot pin secured in said cartridge and extending transversely of said slot, an anchor member having a hub loosely surrounding said pin and adapted for pivotal movement thereon, and cooperating bearing surfaces formed in said slot and on the exterior of said hub, whereby Vsaid pivot pin is relieved of substantially all strain.

9. A blasting cartridge adapted to be positioned within a shot hole and to be discharged therein, said cartridge having a slot formed therein, an anchor dog pivotally mounted `in said slot and adapted to normally lie within the confines of said cartridge blasting cartridge adapted to be poi and to be ing position in response to the discharge of the cartridge, the walls of said, slot being formed to limit both the inward and outward movement of said dog and to afford a, strengthening support for the same when in its outward position.

10. A blasting cartridge substantially as set forth in claim 6 and wherein the said dogs act to substantially reverse the direction of W of the discharged gas, thus producing reaction upon the cartridge tending to hold the same in the desired position.

Signed at Chicago, Illinois, this 20th day of April, 1929.

FRANKH. ARMSTRONG.

projected outwardly into anchorl 

